Mobile devices today can provide a consumer with a wealth of services over those of traditional voice and data services. One such service is the delivery of multimedia content such as video clips and TV programs in general, and in particular, delivery of such content wirelessly. As multimedia content consumption has become more popular, techniques have been developed to enable more efficient delivery of the content to the consumer's mobile device. Currently, the most common delivery mechanisms are broadcasting, live streaming, and downloading.
Broadcast technologies send the same content to a large number of devices at the same time over a broadcast channel. Broadcasting is thus relatively efficient in terms of bandwidth use, though typically requires adapted devices to receive the broadcast content as well as dedicated broadcast networks to deliver the content.
Examples of current broadcast technologies include digital video broadcasting-handheld (DVB-H), digital multimedia broadcasting (DMB), and Multimedia Broadcast Multicast Service (MBMS).
Most mobile streaming services today are based around existing 3G mobile networks, and therefore require little or no modification to existing mobile phones and network. Streaming to mobiles is usually a unicast service, where content is sent in a continuous stream from a server to a single device and played as it arrives. It has several benefits aside from not requiring a dedicated broadcast network, including allowing the user to choose whatever content desired, and near instant access without having to wait for a complete file to be downloaded. However a significant drawback is that since a separate stream is required for each user, available network bandwidth can quickly become used up. Also, a permanent connection is required for users to watch content.
Increasingly, mobile devices are WiFi (IEEE 802.11) enabled and the WiFi connection can be used for video streaming. Streaming over a WiFi connection is relatively fast even when compared to the streaming over 3G connection. It also has the advantage of being much cheaper than streaming over a 3G connection, and many users now have WiFi coverage in their own homes as part of their ADSL connection, and public WiFi hotspots are increasing in number by the day.
Content can also be downloaded onto a device, stored, and then watched later whenever the user chooses. The download can be made over whatever network connection is available to the device, but the most common are over a 3G network connection or WiFi. Downloading has advantages in that both the average instantaneous bit-rate of the content is decoupled from the underlying transfer rate—a higher quality piece of content with a higher data rate can now be consumed—the user simply has to wait longer for that content to arrive. The disadvantage of this system is, of course, that the user now has to wait for the content to arrive.